Created domestic varieties of leaf lettuce in temperate climates (10-15 years later) unfortunately, in modern conditions of climate change has partially lost its test characteristics and does not meet for the modern agricultural production requirements. That is why, the main purpose of the research was to create a highly adaptive source material for the highly adaptive breeding of these vegetable plants. Object of research: leaf lettuce (Lactuca sativa L. var. secalina). Subject of research: 8 mutant samples of lettuce progeny M2-M4, created by the method of chemical and physical mutagenesis on the basis of the variety of domestic breeding Snizhinka. The research was conducted in accordance with the method of VIR for the study of collections of infrequent cultures, according to the working plans according to the current standards. As a result of 3 years of research (2012-2014), 4 mutant samples of leaf lettuce were selected for breeding, which showed a low reaction to growing conditions and a slight increase in yields compared to the original form at 6,85- 7,28 t/ha and 5 promising mutant genotypes, which showed higher plant yield compared to the original form at the level of 8,97-11,14 t/ha depending on the agronomic conditions of cultivation and, therefore, is a valuable starting material for the production of intensive cultivars. The created mutant gene pool is a valuable starting material for the selection of leaf lettuce, namely, for the creation of ecologically-plastic varieties, and varieties of intensive type of cultivation.
seedlings lettuce, adaptive ability, induced mutagenesis, source material for breeding